Device beacon for communication management for peer to peer communications

RELATED APPLICATIONS

This application is a continuation application of U.S. patent application entitled “DEVICE BEACON FOR COMMUNICATION MANAGEMENT FOR PEER TO PEER COMMUNICATIONS”, Ser. No. 12/267,365, and filed on Nov. 7, 2008 which is related to U.S. patent application entitled “DEVICE BEACON FOR HANDOFF MANAGEMENT OF HANDOFFS TO ACCESS NODES”, Ser. No. 12/267,261, and to U.S. patent application entitled “DEVICE BEACON FOR HANDOFF MANAGEMENT OF HANDOFFS TO BASE STATIONS”, Ser. No. 12/267,171, both filed on Nov. 7, 2008 and incorporated by reference in their entirety, herein.

BACKGROUND

The invention relates in general to wireless communication systems and more specifically to device beacon signals in a wireless communication system.

Wireless communication systems may include base stations or access nodes establish communication links to portable wireless communication devices. In peer to peer communications, the portable wireless communication devices communicate directly to each other without accessing a base station or access node. Conventional systems, however, are limited in that presence of one wireless communication device is unknown to another device even though communications between the two devices is advantageous or otherwise desired.

SUMMARY

A wireless communication device transmits a device beacon in accordance with a system timing of a wireless wide area network (WWAN). For one example, the beacon is transmitted relative to WWAN uplink channels of the time-frequency space of the uplink WWAN channel assignment. In response to the reception of the device beacon by another wireless communication device, a peer to peer communication session is established.

BRIEF DESCRIPTION OF THE DRAWINGS

<figref idref="DRAWINGS">FIG. 1A</figref> is a block diagram of a communication system in accordance with an exemplary embodiment of the invention.

<figref idref="DRAWINGS">FIG. 1B</figref> is block diagram of a communication system where the transceiver node is an access node.

<figref idref="DRAWINGS">FIG. 1C</figref> is a communication system where the transceiver node is a mobile wireless communication device.

<figref idref="DRAWINGS">FIG. 2A</figref> is an illustration of an exemplary geographical service area relationship provided by an originating base station and detecting base station where the geographic service area of a detecting base station is within an originating geographic service area of the originating base station.

<figref idref="DRAWINGS">FIG. 2B</figref> is an illustration of an exemplary geographical service area relationship provided by the originating base station and the detecting base station where the geographic service area of a detecting base station overlaps with the originating geographic service area of the originating base station.

<figref idref="DRAWINGS">FIG. 2C</figref> is an illustration of an exemplary geographical service area relationship provided by the originating base station and the detecting base station where the geographic service area of a detecting base station does not overlap with the originating geographic service area of the originating base station.

<figref idref="DRAWINGS">FIG. 3A</figref> is a block diagram of a communication system where the transceiver node is a base station and the beacon is transmitted within the WWAN uplink channel.

<figref idref="DRAWINGS">FIG. 3B</figref> is a block diagram of a communication system where the transceiver node is a base station the beacon is transmitted outside of the WWAN uplink channel.

<figref idref="DRAWINGS">FIG. 4A</figref> is a block diagram of an example of the search message.

<figref idref="DRAWINGS">FIG. 4B</figref> is block diagram of an example of the device proximity.

<figref idref="DRAWINGS">FIG. 5</figref> is flow chart of a method of managing wireless service to a wireless communication device performed at the detecting base station.

<figref idref="DRAWINGS">FIG. 6</figref> is a flow chart of a method of managing communication services to the wireless communication device performed in the system infrastructure.

<figref idref="DRAWINGS">FIG. 7</figref> is block diagram of a communication system where the transceiver node is a WLAN access point and the wireless communication device is a multimode wireless communication device.

<figref idref="DRAWINGS">FIG. 8</figref> is block diagram of a communication system where a device beacon signal is transmitted in a beacon channel that is not a WWAN channel.

<figref idref="DRAWINGS">FIG. 9A</figref> is a block diagram of an example of a wireless communication device n.

<figref idref="DRAWINGS">FIG. 9B</figref> is a block diagram of another example of a wireless communication device invention where the beacon transmitter includes a WWAN uplink transmitter.

<figref idref="DRAWINGS">FIG. 9C</figref> is a block diagram of an example of a multimode wireless communication device where the beacon is transmitted by the WWAN uplink transmitter.

<figref idref="DRAWINGS">FIG. 9D</figref> is a block diagram of an example of another multimode wireless communication device where the beacon is transmitted within a beacon channel that is not a WWAN uplink channel.

<figref idref="DRAWINGS">FIG. 10</figref> is a flow chart of method performed at the wireless communication device where the transceiver node is a base station.

<figref idref="DRAWINGS">FIG. 11</figref> is a flow chart of method performed at the wireless communication device where the transceiver node is a WLAN access point.

<figref idref="DRAWINGS">FIG. 12A</figref>, <figref idref="DRAWINGS">FIG. 12B</figref> and <figref idref="DRAWINGS">FIG. 12C</figref> are graphical illustrations of exemplary relationships between the device beacon and the frequency-time space of the uplink WWAN channel when the WWAN system utilizes OFDM techniques.

<figref idref="DRAWINGS">FIG. 13A</figref> is a block diagram of a beacon generator connected to a beacon transmitter wherein the device beacon is transmitted within the WWAN uplink channel.

<figref idref="DRAWINGS">FIG. 13B</figref> is a block diagram of a beacon generator connected to a beacon transmitter wherein the device beacon is transmitted outside of the WWAN uplink channel.

<figref idref="DRAWINGS">FIG. 14</figref> is a block diagram of a communication system in accordance with another exemplary embodiment of the invention where at least two wireless communication devices are able to communicate through a peer to peer link.

DETAILED DESCRIPTION

<figref idref="DRAWINGS">FIG. 1A</figref> is a block diagram of a communication system <b>100</b> that includes a wide area wireless network (WWAN) <b>102</b>, a transceiver node <b>104</b>, and a wireless communication device <b>106</b>. The WWAN provides wireless communication services to one or more wireless communication devices <b>106</b>. The wireless communication device <b>106</b>, at least periodically, transmits a device beacon <b>108</b> in accordance with a system timing <b>110</b> of the WWAN <b>102</b>. The transceiver node <b>104</b> also obtains the system timing <b>110</b>, either wirelessly or through a wired backhaul. A device beacon detector <b>112</b> within the transceiver node <b>104</b> uses the system timing <b>110</b> to monitor device beacon channels and to receive the device beacon <b>108</b>. As discussed below, the transceiver node <b>104</b> may perform any of several tasks in response to detecting the device beacon <b>108</b> where at least some of the tasks may result in establishing communications between the transceiver node <b>104</b> and the wireless communication device <b>106</b>.

The device beacon <b>108</b> may be transmitted within a WWAN channel or may be transmitted in a separate frequency band outside of the WWAN frequency band. Where the device beacon <b>108</b> is transmitted within a WWAN channel, the device beacon <b>108</b> is transmitted within a time slot and frequency that minimizes interference with other communications within the WWAN <b>102</b>. As discussed below, a suitable technique for such an arrangement includes performing a subcarrier mapping of the device beacon <b>108</b> with the time-frequency space of the uplink WWAN channel assignment for the wireless communication device. Some examples of channels that can be used that are outside the WWAN uplink channels include WLAN channels, WWAN adjacent bands, and channels within unlicensed bands such WiFi and Bluetooth. Also, the wireless communication device may transmit beacons during WWAN idle states and WWAN non-idle states. The device beacon detector <b>112</b> is any device that can detect the device beacon <b>108</b> when the wireless communication device <b>106</b> is sufficiently close to the transceiver node <b>104</b> where the particular implementation depends on the type of device beacon <b>108</b>. For the examples discussed below, the device beacon detector <b>112</b> comprises a receiver configured to receive signals transmitted within the frequency band and with the modulation scheme used to transmit the device beacon <b>108</b>.

The transceiver node <b>104</b> may be any portable, mobile, or fixed communication device that is capable of communicating with the wireless communication device <b>106</b> under the appropriate conditions. For one example discussed below with reference to <figref idref="DRAWINGS">FIG. 1C</figref>, the transceiver node <b>104</b> is another wireless communication device that communicates on the WWAN. For the other examples discussed with reference to <figref idref="DRAWINGS">FIG. 1B</figref>, the transceiver node <b>104</b> is an access node providing wireless communication service where the access node may be a base station operating within the WWAN such as a femtocell base station or may be an access point of a wireless local area network (WLAN).

<figref idref="DRAWINGS">FIG. 1B</figref> is a block diagram of the communication system <b>100</b> where the transceiver node <b>104</b> is an access node <b>114</b>. The communication system <b>100</b> includes at least one access node <b>114</b> and at least one WWAN base station <b>116</b> where the access node <b>114</b> provides wireless communication service within a geographical service area that is smaller than the geographical service area in which the base station <b>116</b> provides wireless service. The communication system <b>100</b> may be implemented in accordance with any of numerous technologies and communication standards where the access node <b>114</b> may use the same or different standard than used by the base station <b>116</b>. Further, the access node <b>114</b> may be part of a separate network or may be part of the same network as the base station <b>116</b>. The access node <b>114</b> may be self-managed or may be managed by the system infrastructure <b>118</b> which may also manage the base station <b>116</b>. In some examples, the access node <b>114</b> is a femtocell base station operating in the same network where the base station <b>116</b> operates as a macrocell base station. In another example, the access node <b>114</b> is a wireless access point providing wireless service in a wireless local area network (WLAN) and the base station <b>116</b> provides service in a wireless wide area network (WWAN) using a different technology and standard than used by the WLAN access point. The access node <b>114</b>, therefore, can be any base station, transceiver, or other communication device that provides wireless communication service to a wireless communication device to connect the wireless communication device to other devices and/or a communication network.

The system infrastructure <b>118</b> is connected to one or more base stations <b>116</b> and access nodes <b>114</b>. Communications between the base station <b>116</b> and wireless communication devices <b>106</b> are at least partially managed by the system infrastructure <b>118</b> for the example. A controller <b>120</b> within the system infrastructure <b>118</b> at least includes hardware, software and/or firmware for receiving and sending control messages. The controller <b>120</b> may include at least portions of a BSC and a MSC. For the example discussed herein, the controller <b>120</b> is the equipment within the communication system <b>100</b> that performs wireless device paging functions and generates paging channel messages.

The wireless communication device <b>106</b> transmits a device beacon <b>108</b> that is based on timing information <b>122</b> received from the base station <b>116</b>. Timing information is derived at the wireless communication device by receiving WWAN downlink signals <b>122</b> transmitted by the base station <b>116</b>. Examples of suitable methods for acquiring WWAN system timing include receiving a sync channel or a sync-type channel. A downlink control signal may be received, for example, and accurate timing derived from the signal. In some circumstances, an early-late gate method is used to derive timing which uses an auto-correlation function. For systems that transmit information in a packetized mode, the synchronization processes may be aided by a sync preamble consisting of a training sequence. These training sequences typically have appropriate cyclic guard intervals. The preambles are periodically transmitted in between data symbols. After acquiring a coarse timing, the wireless communication may implement tracking mode where it tracks/adjusts and maintains the timing information. When the wireless communication device <b>106</b> is sufficiently close to the access node <b>114</b>, the access node <b>114</b> can receive the device beacon <b>108</b> transmitted by the wireless communication device <b>106</b>. The access node <b>114</b>, therefore, at least periodically attempts to receive signals in the designated device beacon channels <b>124</b>. As discussed, the device beacon <b>108</b> may be transmitted within designated WWAN uplink channels or outside of the WWAN band. At the appropriate times (or continuously), the device beacon detector <b>112</b> tunes to the appropriate frequencies and/or uses the appropriate scrambling codes to monitor the device beacon channels <b>124</b> where device beacons <b>108</b> may be present. The device beacon detector <b>112</b>, therefore, is any device that is able to monitor the device beacon channels <b>124</b> and determine when a device beacon <b>108</b> is present. For the examples discussed herein, the device beacon is deterministically transmitted such that a receiver can easily find and acquire beacon signals as needed. The information defining the device beacon assigned parameters may be broadcasted by the WWAN using control channels. Such broadcasts may be autonomous or in response to a request from a WLAN Access Point or femtocell base station. Examples of beacon parameters include beacon transmission times and periods as well as subcarrier and frequency information.

The access node <b>114</b> derives the system timing <b>110</b> either through a backhaul from the system infrastructure <b>118</b> or by monitoring the base station downlink signals <b>122</b>. The WWAN downlink signal <b>122</b> from the base station <b>116</b> to the access node <b>114</b> is shown as a dashed line to illustrate that the signal may or may not be received by the access node <b>114</b>. Where the access node <b>114</b> is femtocell base station, the system timing <b>110</b> is typically obtained through backhaul, GPS or the WWAN. In some circumstances where the access node <b>114</b> is a WLAN assess point, deriving the timing from WWAN downlink signals <b>122</b> may be more efficient than obtaining the system timing directly from the system infrastructure <b>118</b>.

The reception of the device beacon signal <b>108</b> invokes the acquisition of wireless service from the access node <b>114</b> by the wireless communication device <b>106</b>. In the examples discussed, the access node <b>114</b> informs the system infrastructure <b>118</b> of the detection after detecting the device beacon <b>108</b>. In response, the system infrastructure <b>118</b> transmits a search message <b>126</b> to the wireless communication device <b>106</b> that adjusts the searching scheme used by the wireless communication device <b>106</b> to search for alternate wireless service. Where the wireless communication device <b>106</b> is a dual mode device searching for a WLAN, for example, the search message <b>126</b> may result in an activation of the WLAN receiver to search for WLAN signals. Where the access node <b>114</b> is a base station connected on the same cellular network as the base station <b>116</b>, the wireless communication device <b>106</b> may change search parameters of the searching scheme used to search for alternate base stations in response to the search message <b>126</b>. Additional information may be processed by the access node <b>114</b> and/or the system infrastructure <b>118</b> before messages are transmitted by the system infrastructure <b>118</b> and/or the wireless communication device <b>106</b>. As discussed below, for example, the capacity of the access node <b>114</b> and the bandwidth requirements of the wireless communication device <b>106</b> may be evaluated before invoking a handoff to the access node <b>114</b>. In some situations, the detection of the device beacon signal may invoke additional procedures or mechanisms. For example, in situations where the access node is not transmitting a pilot signal until services are to be provided, the detection of the beacon invokes the transmission of the pilot signal.

<figref idref="DRAWINGS">FIG. 1C</figref> is a block diagram of the communication system <b>100</b> where the transceiver node <b>104</b> is a mobile wireless communication device <b>128</b>. The mobile wireless communication device <b>128</b> is any mobile or portable device that is capable of receiving WWAN downlink signals <b>130</b> and may be, for example, a handset, phone, wireless personal digital assistant (PDA), wireless modem, or wireless laptop computer. In some circumstances, the mobile wireless communication device <b>128</b> may be capable of communication on the WWAN <b>102</b>. In other situations, however, the mobile wireless communication device <b>128</b> may include adequate electronics to receive the WWAN downlink signals <b>122</b> but may be configured to operate on a different network where the network may use the same or different technology and/or protocol than the WWAN <b>102</b>. For example, the mobile wireless communication device <b>128</b> may be a WLAN device that operates in accordance with WiFi but that also includes WWAN receiver. Further, the mobile wireless communication device <b>128</b> may be a multi-mode wireless communication device such as a dual-mode phone capable of operating within a WWAN and a WLAN. Since both of the wireless communication devices <b>106</b>, <b>128</b> receive downlink signals <b>122</b>, <b>130</b> from the WWAN base station <b>116</b>, the two devices <b>106</b>, <b>128</b> both receive system timing information <b>110</b> from the WWAN. Accordingly, the system timing <b>110</b> is used as a reference for transmitting and receiving the device beacon <b>108</b>.

After the beacon detecting wireless communication device <b>128</b> detects the device beacon <b>108</b>, a peer to peer session is established between the wireless communication device <b>106</b> and the beacon detecting wireless communication device <b>128</b>. Peer to peer communication includes peer to peer communication <b>132</b> between the two devices <b>106</b>, <b>128</b> without transmitting data through a network. The arrow representing peer to peer communication is shown with dashed lines in <figref idref="DRAWINGS">FIG. 1C</figref> to illustrate that the communications <b>132</b> are not established until after the device beacon <b>108</b> is detected. The peer to peer session may be established using any of several techniques and signaling schemes. For example, a device detection message may be sent to the WWAN which invokes a session establishment message that is transmitted by the WWAN to the wireless communication device <b>106</b>. In response to the session establishment message, the wireless communication device <b>106</b> transmits and/or receives messages to establish the peer to peer session. In some situations, the beacon detecting wireless communication device <b>128</b> sends a message directly to the wireless communication device <b>106</b> without using the WWAN.

<figref idref="DRAWINGS">FIG. 2A</figref>, <figref idref="DRAWINGS">FIG. 2B</figref> and <figref idref="DRAWINGS">FIG. 2C</figref> are depictions of exemplary geographical service area relationships <b>200</b>, <b>206</b>, <b>208</b> provided by the WWAN <b>102</b> and the transceiver node <b>104</b>. A WWAN geographical service area <b>202</b> provided by the WWAN base station <b>116</b> and a geographic service area <b>204</b> provided by the transceiver node <b>104</b> may have any of numerous shapes, sizes, and configurations. Accordingly, the clouds representing the service areas generally illustrate the relationships between the service areas and do not necessarily depict the actual shapes of the service areas. Further, the service areas may contain holes of coverage where service is unavailable. In the interest of clarity and brevity, such features are not illustrated in the figures. In <figref idref="DRAWINGS">FIG. 2A</figref>, the service area <b>204</b> of the detecting transceiver node <b>104</b> is completely within the service area <b>202</b> provided by the WWAN <b>102</b>. Such service area relationships <b>200</b> often occur where some base stations within the communication system <b>100</b> provide smaller service regions such as microcell, picocell, and femtocell configurations. A femtocell arrangement, for example, may include a femtocell base station (transceiver node <b>104</b>) located at a residence where the femtocell is a service area for devices used by device users living at the residence. When the wireless communication devices are outside the service area <b>204</b>, service is provided by larger macrocells (e.g. reference base station <b>116</b>). When the authorized wireless communication device is at the residence, however, service is provided by the transceiver node <b>104</b> presenting the smaller femtocell service area <b>204</b>. Further, the relationship <b>200</b> is likely to occur where the transceiver node <b>104</b> is a wireless communication device <b>128</b>. In such situations, the geographic service area is a geographic area within which another wireless communication device can engage in a per-to-peer communication session with the wireless communication device <b>128</b>. Accordingly, in most situations, the service area <b>204</b> of the transceiver node <b>104</b> will be completely within the service area <b>202</b> of the base station <b>116</b>. In some situations, however, the service area <b>204</b> may be partially overlapping with the service area <b>202</b> as shown in <figref idref="DRAWINGS">FIG. 2B</figref> or may be non-overlapping but adjacent to the service area <b>202</b> as shown in <figref idref="DRAWINGS">FIG. 2C</figref>.

<figref idref="DRAWINGS">FIG. 3A</figref> is a block diagram of a communication system <b>300</b> where the transceiver node <b>104</b> (access node <b>114</b>) is a base station <b>302</b> such as a femtocell base station, picocell base station, or microcell base station. The system <b>300</b> may be implemented using any variety of communication technologies and cell sizes. For the example discussed with reference to <figref idref="DRAWINGS">FIG. 3A</figref>, the base station <b>302</b> provides wireless service within a femtocell and the base station <b>116</b> provides service within a macrocell. In the interest of clarity, the base station <b>302</b> that detects the device beacon <b>108</b> is referred to as the detecting base station <b>302</b> and the base station <b>116</b> providing the system timing <b>110</b> to the wireless communication device <b>106</b> is referred to as the reference base station <b>116</b>. The base stations <b>302</b>, <b>116</b> operate in accordance with OFDM protocols and standards such as IEEE802.16 and 3GPP LTE. Other communication standards and protocols, however, may be used in some circumstances. Examples of other suitable communication standards include CDMA standards such as cdma20001×, 1×EV-DO and W-CDMA, and GSM standards. The term macrocell is used primarily to distinguish this group of diverse technologies from picocells and femtocells that typically have smaller service areas on the order of 100 to 300 feet per base station. Accordingly, the reference base station <b>116</b> is any base station that provides wireless communication services within relatively large geographical areas as compared to the geographical service area provided by the base station <b>302</b> in the example of <figref idref="DRAWINGS">FIG. 3A</figref>. The functional blocks of <figref idref="DRAWINGS">FIG. 3A</figref> may be implemented using any combination of hardware, software and/or firmware. Two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices. For example, at least portions of the functions of the system infrastructure <b>118</b> and controller <b>120</b> may be performed by the base station <b>116</b>, a base station controller, or an MSC in some circumstances.

The reference base station <b>116</b> transmits downlink link (forward) signals <b>122</b> to, and receives uplink (reverse link) signals <b>304</b> from, one or more wireless communication devices to provide wireless communication service. The wireless communication device <b>106</b> may be in any of several states while receiving the WWAN downlink signals that provide system timing. The operational states of the wireless communication device <b>106</b> may include idle states, dormant states, active states and other traffic and non-traffic states. The wireless communication device <b>106</b> generates and transmits the device beacon <b>108</b> in accordance with the system timing. The system timing includes at least the timing reference as well as time slot and channel assignment. For the example discussed with reference to <figref idref="DRAWINGS">FIG. 3A</figref>, device beacon <b>108</b> is transmitted at a designated time and channel (subcarrier) within the uplink WWAN time-frequency space. For the example discussed with reference to <figref idref="DRAWINGS">FIG. 3B</figref> below, the device beacon <b>108</b> is transmitted outside of the uplink channel but in accordance with the WWAN system timing.

The system infrastructure <b>118</b> includes the controller <b>120</b> that may be implemented as a mobile switching center (MSC), a combination of an MSC and base station controllers (BSCs), or other similar communication controllers and/or servers. The controller <b>120</b> is connected to the base stations <b>302</b>, <b>116</b> through the system infrastructure <b>118</b> and manages communications within the system <b>300</b>. Although the controller <b>120</b> is illustrated as part of the system infrastructure <b>118</b>, it may be part of the base station <b>116</b> or collocated with the base station <b>116</b>. The controller <b>120</b> may include, or may be part of, the MSC, BSC or other infrastructure. The controller <b>120</b> includes the hardware and software for generating the search message <b>126</b> and, for this example, is the same equipment used to generate paging channel messages.

A network interface <b>306</b> within the detecting base station <b>302</b> facilitates communication with an IP network <b>308</b> through an access router <b>310</b>. The network interface <b>306</b> provides packet data communications and facilitates access to the Internet and to an access gateway <b>312</b> in the system infrastructure <b>118</b> through the access router <b>310</b>. In some circumstances the access router <b>310</b> may be implemented as part of the network interface and the network interface <b>306</b> may directly access the Internet. The access router <b>310</b> may be connected to several base stations and provides communication management and control functions to the detecting base station <b>302</b>. In some circumstances, the connection between the access gateway <b>312</b> and the base station <b>302</b> may include a wireless communication link such as satellite communication link or point-to-point microwave link, for example. Also, in some situations, circuit switched connections may be used to connect the detecting base station <b>302</b> to the system infrastructure <b>118</b>. In a typical arrangement, the detecting base station <b>302</b> is connected to the Internet through an Internet Service Provider (ISP) service provided by a digital subscriber line (DSL) or CATV connection. Accordingly, the access router <b>310</b> is a DSL modem or cable modem in the typical arrangement. In the example, therefore, the system infrastructure <b>118</b> comprises a packet switched core network that includes at least one access gateway <b>312</b>. The access gateway <b>312</b> is a communication interface that allows the base station <b>302</b> to communicate with the system infrastructure <b>118</b>.

The wireless communication device <b>106</b> is any type of communication device that is capable of communicating with the base stations <b>302</b>, <b>116</b>. The wireless communication device <b>106</b>, sometimes referred to as an access terminal, may be a wireless modem, a personal digital assistant (PDA), cellular telephone, or other such device. Examples of suitable wireless communication devices are provided below.

In addition to the functions and features discussed herein, the detecting base station <b>302</b> operates in accordance with the communication protocols of the communication system <b>300</b> and is a femtocell base station. The detecting base station <b>302</b> includes a controller <b>314</b>, memory <b>316</b>, WWAN transceiver <b>318</b>, such as cellular transceiver, and the network interface <b>306</b> in addition to other devices and software for performing the functions of the base station <b>302</b>. The cellular transceiver <b>318</b> includes an uplink receiver <b>320</b> and a downlink transmitter <b>322</b>. The downlink transmitter <b>322</b> transmits WWAN downlink signals <b>132</b> to wireless communication devices such as the wireless communication device <b>106</b>.

In addition to other information, the memory <b>316</b> stores communication device identification values corresponding to each wireless communication device <b>106</b> that is authorized to receive service from the base station <b>302</b>. The communication device identification value may include an electronic serial number (ESN), Mobile station Equipment Identifier (MEID) or International Mobile Subscriber Identity (IMSI) or other unique data identifying the wireless communication device <b>106</b>. An example of a group of identification values stored in memory <b>316</b> includes a collection of ESNs corresponding to the communication devices of the family members of a household where the base station <b>302</b> provides service. The identification values may be stored at the base station <b>302</b> using any of numerous techniques. An example of a suitable method of storing the values includes storing the values during an initialization procedure performed when the base station <b>302</b> is installed. The identification values may be provided, at least partially, by the core network or the macrocell base station <b>116</b>. In some implementations, the identification values may be omitted or the base station <b>302</b> may allow communication devices that do not have corresponding identification values stored at the base station <b>302</b> to receive service from the base station <b>302</b>.

During operation, the detecting base station <b>302</b> monitors, at least periodically, a device beacon channel <b>124</b> which is a wireless channel that may include the device beacon signal <b>108</b>. For the example of <figref idref="DRAWINGS">FIG. 3A</figref>, the device beacon signal <b>108</b> is within a sub-carrier time slot. In some circumstances, no other channel is assigned for the other frequencies during the time slot assigned for the device beacon. Such a scenario increases the likelihood of the detecting base station <b>302</b> to detect the device beacon signal <b>108</b> since all of the device beacon energy is concentrated at a particular frequency with no other concurrently transmitted signals present. The assignment of subcarriers for the beacon is established at the base band frequencies. Accordingly, the actual transmitted signal at the radio frequencies (RF) may include a wideband signal. The device beacon detector <b>112</b> is formed by at least portions of the controller <b>314</b>, memory <b>316</b> and uplink receiver <b>320</b>. Since the detecting base station <b>302</b> is synchronized with the system infrastructure <b>118</b>, the cellular transceiver <b>318</b> has adequate system timing information to determine the time slot boundary and the timing of uplink signals. The timing facilitates non-blind beacon detection at the receiver. With appropriate beacon designs, blind detection may also be performed. In some circumstances, the device beacon detector <b>112</b> may only search for beacons signals transmitted from wireless communication devices that are authorized to use the detecting base station <b>302</b>. An authorized list of serial numbers or other device identifiers are stored in memory <b>316</b> at the detecting base station <b>302</b>.

In response to detecting the device beacon signal <b>108</b>, the detecting base station <b>302</b> sends a device proximity message <b>324</b> to the controller <b>120</b> which invokes the reference base station <b>116</b> to transmit the search message <b>126</b> to the wireless communication device <b>106</b>. For this example, the controller <b>314</b> determines if the device beacon signal <b>108</b> is successfully received at the detecting base station <b>302</b>. If the signal can be received, the controller <b>314</b> determines that the wireless communication device <b>106</b> is sufficiently close to receive service from the base station <b>302</b>. In some cases, the device beacon signal may be detected and received even though the wireless communication device <b>106</b> is not within the service area of the base station <b>302</b>. In these circumstances, the wireless communication device <b>106</b> may unsuccessfully attempt to acquire service from the base station <b>302</b> after receiving the search message <b>126</b> from the reference base station <b>116</b>. The controller <b>314</b> determines, or at least estimates, the proximity of the authorized wireless communication device <b>106</b> to the detecting base station <b>302</b> based on one or more characteristics of the uplink signal. In the exemplary embodiment, the detection of an uplink signal from the communication device <b>106</b> is sufficient to determine that the communication device <b>106</b> is within a proximity range. The proximity is used to determine whether the communication device <b>106</b> is possibly within range of the base station <b>302</b> and at least possibly able to receive communication service from the base station <b>302</b>. Therefore, the controller <b>314</b> at least determines whether the communication device <b>106</b> is possibly within range of the base station <b>302</b>. If the controller <b>314</b> determines that the wireless communication device <b>106</b> is possibly in range, the device proximity message <b>324</b> is sent to the controller <b>120</b> in the system infrastructure <b>118</b> which results in the transmission of the search message <b>126</b> to the wireless communication device <b>106</b>.

The controller <b>314</b> may determine whether to transmit the device proximity message <b>324</b> based on factors other than proximity of the wireless communication device <b>106</b> or the detection of the device beacon signal <b>108</b>. For example, factors may include the available capacity of the detecting base station <b>302</b>, core network requirements, required bandwidth of the wireless communication device communications, and availability of other base stations or communication service providers in the area. Accordingly, the base station <b>302</b> may not transmit the device proximity message <b>324</b> even if the wireless communication device <b>106</b> is within range in some circumstances. In some situations, the device proximity message <b>324</b> is transmitted every time a wireless communication device <b>106</b> is detected by the detecting base station <b>302</b> and the system infrastructure <b>118</b> determines whether to transmit the search message <b>126</b>.

The device proximity message <b>324</b> is generated by the controller <b>314</b> and transmitted through the network interface <b>306</b>, through the IP network <b>308</b> and/or the access router <b>310</b> to the access gateway <b>312</b>. The access gateway <b>312</b> routes the device proximity message <b>324</b> through the system infrastructure <b>118</b> to the controller <b>120</b>. For the discussed example, the controller <b>120</b> is the same equipment that is used to generate paging messages to the wireless communication device <b>106</b>. The controller <b>120</b> receives the device proximity message <b>324</b> and extracts the appropriate information. In response to the device proximity message <b>324</b>, the controller <b>120</b> generates the search message <b>126</b> which is transmitted from the reference base station <b>116</b> to the wireless communication device <b>106</b>. The search message <b>126</b> triggers an adjustment of the wireless communication device searching scheme that the wireless communication device <b>106</b> employs for searching for alternate base stations. The wireless communication device <b>106</b>, therefore, changes one or more searching parameters of the searching scheme in response to receiving the search message <b>126</b>. Any combination of numerous parameters can be adjusted where the adjustments increase the likelihood of the wireless communication device <b>106</b> detecting a signal transmitted by the detecting base station <b>302</b>. The search message <b>126</b> may result in a change in the search scheme to devote more resources to search for an alternate base station or may result in a change in resources to search for the specific detecting base station <b>302</b>. In some circumstances, the search message <b>126</b> may specifically instruct the wireless communication device <b>106</b> to search for the detecting base station <b>302</b>.

For the example, the search message <b>126</b> is transmitted using the paging channel. Any suitable downlink channel monitored by the wireless communication device <b>106</b> during the non-traffic state, however, may be used. The wireless communication device <b>106</b> searches for signals transmitted by alternate base stations in accordance with the searching scheme. Alternate base station signals from frequencies and/or technologies different than those by the base station <b>116</b> may be searched. The wireless communication device <b>106</b> searches for pilot signals although other signals may be searched. For example, the wireless communication device <b>106</b> may search for base station beacon signals in some situations. Examples of searching parameters include a total time period for searching, time periods for searching particular frequencies, the frequency of searching, the frequency of searching particular frequencies, the groups of frequencies searched, the portions of channels searched, the receiver settings for searching and type of communication technology. Other searching parameters will be apparent to those skilled in the art based on these teachings. As discussed in further detail below with reference to <figref idref="DRAWINGS">FIG. 4A</figref>, therefore, the search message <b>126</b> includes information that results in an adjustment of one or more of the search parameters.

For the present example, device proximity message <b>324</b> are sent only in response to receiving device beacon signals <b>108</b> from authorized users of the detecting base station <b>302</b>. The search message <b>126</b> is sent to the wireless communication device <b>106</b> in response to receiving the device proximity message <b>324</b> at the controller <b>120</b>. In some situations, however, additional criteria may be evaluated before sending the device proximity message <b>324</b>, the search message <b>126</b>, or before sending both. As discussed below, for example, the detecting base station <b>302</b> may evaluate one or more parameters to determine the proximity of the wireless communication device <b>106</b> to the detecting base station <b>302</b> and only send the device proximity message <b>324</b> if the calculated proximity is less than a threshold. Also, the controller <b>120</b> may evaluate system conditions and refrain from sending the search message <b>126</b> if certain system conditions are not met.

Examples of data that may be evaluated by the detecting base station <b>302</b> include the capacity of the detecting base station <b>302</b>, bandwidth requirements of the wireless communication device <b>106</b> and a calculated or estimated proximity of the wireless communication device <b>106</b> to the detecting base station <b>302</b>. Accordingly, the detecting base station <b>302</b> may evaluate a characteristic of the device beacon signal <b>108</b> to determine whether to transmit the device proximity message <b>324</b>. In the example, the reception of the device beacon signal <b>108</b> by the UL receiver <b>320</b> is sufficient to determine that the wireless communication device <b>106</b> is present and that the device proximity message <b>324</b> should be transmitted. In other circumstances, other signal characteristics may be evaluated to determine the proximity. Therefore, a characteristic of the device beacon signal <b>108</b> may be any of numerous parameters with any of numerous thresholds depending on the particular implementation and the characteristic may be whether the device beacon signal <b>108</b> is detectable by the base station receiver <b>320</b>. Examples of other characteristics include a signal to noise ratio (SNR), bit error rate (BER), power level, signal propagation time, and presence of particular data. An example of technique for determining the proximity is discussed in U.S. patent application Ser. No. 11/565,266 entitled “APPARATUS, SYSTEM AND METHOD FOR MANAGING WIRELESS LOCAL AREA NETWORK SERVICE TO A MULTI-MODE PORTABLE COMMUNICATION DEVICE”, filed on Nov. 30, 2006, and incorporated by reference in its entirety herein.

The device proximity message <b>324</b> and search message <b>126</b> may have any of numerous relationships and each message may be dependent on the information within, the format of, and/or other characteristics of the other message. For example, the device proximity message <b>324</b> and the search message <b>126</b> may be the same message in some circumstances. Such a situation occurs where the device proximity message <b>324</b> is an SMS message sent directly to the wireless communication device <b>106</b> indicating that the device beacon signal <b>108</b> transmitted from the device <b>106</b> has been detected by the detecting base station <b>302</b>. The wireless communication device <b>106</b> interprets the device proximity message <b>324</b> as a search message <b>126</b> indicating that the search parameters should be changed. Transmitting the search message <b>126</b> within the paging channel, however, allows for minimizing power consumption since additional resources are not invoked to receive SMS messages.

After receiving the search message <b>126</b>, the wireless communication device <b>106</b> searches for an alternate base station in accordance with the adjusted search scheme. In response to the search message <b>126</b>, the wireless communication device <b>106</b> activates the appropriate circuitry to receive signals transmitted by the detecting base station <b>302</b> such as a beacon pilot signal or communication pilot signals. In most situations, such circuitry is periodically activated in accordance with the search scheme to the reception of the search message and the search message does not directly trigger the activation of the receive circuitry. The adjusted search scheme, however, may result in more frequent activation of the circuitry. The detecting base station <b>302</b> generates and transmits a communication pilot signal which provides control and timing information to the wireless communication device <b>106</b>. In some circumstances, the detecting base station <b>302</b> may refrain from transmitting pilot signals until a wireless communication device <b>106</b> is detected and the proximity message <b>304</b> is sent. In addition, the detecting base station <b>302</b> may transmit a base station beacon pilot signal. After the detecting base station <b>302</b> is found by the wireless communication device <b>106</b>, the wireless communication device <b>106</b> may engage in a handoff procedure where, after a determination that the wireless communication device <b>106</b> should be handed off to the detecting base station <b>302</b>, the system <b>300</b> establishes wireless service to the wireless communication device <b>106</b> from the detecting base station <b>302</b>.

<figref idref="DRAWINGS">FIG. 3B</figref> is a block diagram of a communication system <b>350</b> where the transceiver node <b>104</b> (access node <b>114</b>) is a base station <b>352</b> such as a femtocell base station, picocell base station, or microcell base station and where the device beacon is transmitted outside of the WWAN uplink frequency band. The system <b>350</b> is similar to the system <b>300</b> discussed with reference to <figref idref="DRAWINGS">FIG. 3A</figref> except that the detecting base station <b>302</b> includes a device beacon detector <b>112</b> that detects device beacons <b>108</b> outside of the WWAN uplink frequency band. For the example of <figref idref="DRAWINGS">FIG. 3B</figref>, therefore, the wireless communication device <b>106</b> transmits a device beacon with a frequency band outside of the WWAN uplink frequency band. Examples of suitable frequency bands include Bluetooth frequency bands and WLAN frequency bands. The device beacon detector <b>112</b> includes a receiver that can receive the signals transmitted within the device beacon frequency band. After detecting the device beacon, the base station <b>302</b> may perform the functions discussed above with reference to <figref idref="DRAWINGS">FIG. 3A</figref>. In some situations, detecting base station may not be transmitting or receiving any WWAN signals until after detection of the device beacon <b>108</b>. Accordingly, the WWAN pilot signal <b>132</b> may be transmitted in response to the detection of the device beacon signal <b>108</b>.

<figref idref="DRAWINGS">FIG. 4A</figref> is a block diagram of the search message <b>126</b> where the search message <b>126</b> is transmitted within a paging channel message <b>400</b>. The search message <b>126</b> may contain any of several types of information, may have any of numerous formats, and may be transmitted using a variety of channels and signals. For this example, the search message <b>126</b> is contained within the message body <b>402</b> of a paging channel message <b>400</b> in accordance with one or more OFDMA standards. The paging channel is allocated a set of time-frequency bins where each paging channel message <b>400</b> includes a header field <b>404</b>, a message body <b>402</b>, and a cyclic redundancy check (CRC) <b>406</b>.

For the example, a search message indicator <b>408</b> may be included in the header <b>404</b>. The header <b>404</b> may also include message length information. Typically, length is kept constant for paging messages.]. The search message indicator <b>408</b> is any number of bits that indicates to the wireless communication device <b>106</b> that the paging message is a search message <b>126</b>. The search information includes information related to the search scheme adjustment. In some cases, the search message indicator <b>408</b> is sufficient to notify the wireless communication device <b>106</b> of a need to adjust the searching scheme and the search information <b>410</b> may be omitted. The search information, however, may include any of numerous parameters related to the adjusting the searching scheme. As discussed below in further detail, the search information <b>410</b> may include information that identifies one or more base stations that should be searched or frequencies that should be searched.

The search message <b>126</b> includes information that results in an adjustment of one or more of the search parameters. In some situations, the search message <b>126</b> may only indicate that a more robust search should be performed and the wireless communication device <b>106</b> adjusts searching resources in response. The search information <b>410</b> may be omitted in this case. The search change may be a preprogrammed adjustment or a dynamic adjustment based on other criteria observed by the wireless communication device <b>106</b>. For example, if some detection of energy had been recently observed in a particular channel, the adjustment in search parameters may be adjusted to more heavily target resources to searching that particular channel as compared to the resources that would have been applied to the channel if the search message were not received. In an example where the search scheme is preprogrammed that is not based on other criteria, the wireless communication device may search in accordance with a scheme utilized prior to receiving the search message <b>126</b> but may increase search times or reduce the periods between searches.

The search message <b>126</b> may also include search information <b>410</b> identifying a group of base stations that may be available. Such an indication may be a specific identifier specifically identifying one or base stations or may be a general identification identifying a group of base stations such as an identifier indicating all authorized femtocell base stations. Since the wireless communication device <b>106</b> includes a list of all femtocell base stations that the device is authorized to access, a general identifier will provide sufficient information for identifying specific base stations.

In some circumstances, the search message <b>126</b> may indicate specific frequencies. A pilot frequency or beacon frequency of the detecting base station <b>302</b> may be identified, for example.

The wireless communication device <b>106</b> extracts the information from the search message <b>126</b> and adjusts the searching scheme in accordance with search message <b>126</b>. The adjustment may include any of numerous parameter changes where some examples include adjusting one or more of the following: frequencies searched, channels searched, period between searches, period between searches of specific frequencies, time period of search, time period for search at specific frequencies, search offsets, location of starting search in the search-space, and searcher receiver settings. In circumstances where the wireless communication device <b>106</b> searches for service from a system utilizing a different communication technology and universal searcher is used, similar parameters may be adjusted. Where a new searcher is invoked for the alternate technology base station, the parameters may also include the timing of the activation of the new searcher.

<figref idref="DRAWINGS">FIG. 4B</figref> is block diagram of a device proximity message <b>324</b> that includes a message identifier <b>452</b>, and a device identifier <b>454</b>. In some cases, proximity data <b>456</b> may also be included. The proximity data <b>456</b> is illustrated with dashed lines to indicate that this feature is optional. The device proximity message <b>324</b> may have any of numerous formats and may be sent using any suitable signaling method. The message identifier <b>452</b> includes any combination of data that indicates to the controller <b>120</b> that the message <b>450</b> is a device proximity message <b>324</b>. Accordingly, the message identifier <b>452</b> may be a single bit flag in some circumstances. The device identifier <b>454</b> includes data that identifies the wireless communication device <b>106</b> that has been detected by the detecting base station <b>302</b>. One example of a device identifier <b>454</b> is a device serial number.

<figref idref="DRAWINGS">FIG. 5</figref> is flow chart of a method of managing wireless service to a wireless communication device <b>106</b> performed at the detecting base station <b>302</b>. The method may be performed by any combination of hardware, software and/or firmware. The order of the steps discussed below may be varied and one or more steps may be performed simultaneously in some circumstances. In the exemplary embodiment, the method is performed, at least in part, by executing code on the controller <b>314</b> in the detecting base station <b>302</b>.

At step <b>502</b>, the wireless channel that may contain a device beacon signal <b>108</b> is monitored. The uplink receiver <b>320</b> attempts to demodulate and/or decode incoming signals within the wireless communication channel. The WWAN system timing is applied to receive the monitor the beacon channels. In this example, the uplink receiver <b>320</b> is tuned to decode any uplink signals <b>304</b> transmitted from any of the communication devices <b>106</b> in the user list stored in memory <b>316</b>. The long code masks derived with the device identification values are applied to incoming signals until an incoming device beacon signal <b>108</b> is detected.

At step <b>504</b>, it is determined whether a device beacon signal <b>108</b> has been detected. In this example, the controller <b>314</b> determines that device beacon signal has been received if an incoming uplink signal can be decoded and determined to be a beacon signal transmitted from an authorized wireless communication device <b>106</b>. If a device beacon signal <b>108</b> has been received, the method continues at step <b>506</b>. Otherwise, the method returns to step <b>502</b> to continue monitoring the device beacon channel.

At step <b>506</b>, it is determined whether the device proximity message <b>324</b> should be transmitted. In some situations, step <b>506</b> can be omitted and the device proximity message <b>324</b> may be transmitted when the device beacon signal <b>108</b> is detected. This procedure is discussed with reference to <figref idref="DRAWINGS">FIG. 8</figref>. In other situations, however, additional processing or communication is invoked before the device proximity message <b>324</b> is transmitted. For example, system conditions of the detecting base station <b>302</b>, other base stations, the core network, and/or alternate networks can be evaluated to determine whether a handoff to the detecting base station <b>302</b> is desired. An example of such a procedure is discussed with reference to <figref idref="DRAWINGS">FIG. 9</figref>. If it is determined that the device proximity message <b>324</b> should be transmitted, the method continues at step <b>508</b>. Otherwise, the method returns to step <b>502</b>. In some circumstances, a response may be sent to the beacon-transmitting wireless communication device. An ACK may be sent, for example, with an appropriate message that assists the wireless communication device in finding the detecting-device. This ACK-message can be transmitted in WWAN or WLAN frequency or any other frequency (pre-defined)].

At step <b>508</b>, the device proximity message <b>324</b> is sent to the system infrastructure. The device proximity message <b>324</b> at least identifies the wireless communication device <b>106</b> and indicates that the wireless communication device <b>106</b> may be within, or near, the service area of the detecting base station <b>302</b>.

<figref idref="DRAWINGS">FIG. 6</figref> is a flow chart of a method of managing communication services to the wireless communication device <b>106</b> performed in the system infrastructure <b>118</b>. The method may be performed by any combination of hardware, software and/or firmware. The order of the steps discussed below may be varied and one or more steps may be performed simultaneously in some circumstances. In this example, the method is performed, at least in part, by executing code on the controller <b>120</b> in the system infrastructure <b>118</b>.

At step <b>602</b>, the device proximity message <b>324</b> is received from the detecting base station <b>302</b>. As described above, the device proximity message <b>324</b> is sent through the IP network <b>308</b> and routed through the access gateway <b>312</b> to the controller <b>120</b>. The controller <b>120</b> extracts information from the device proximity message <b>324</b> which includes at least information identifying the wireless communication device <b>106</b>.

At step <b>604</b>, it is determined whether the search message <b>126</b> should be transmitted to the wireless communication device <b>106</b>. The controller <b>120</b> may evaluate any number of factors in accordance with known techniques for managing handoffs and communication resources in determining whether to transmit the search message. In some circumstances, the threshold may be relatively low and the controller <b>120</b> determines to send the search message <b>126</b> solely in response to receiving the device proximity message <b>324</b>. In other circumstances, the controller <b>120</b> may apply the same criteria as used to determine whether to handoff a device from one base station to another. Some examples of criteria that may be evaluated by the controller <b>120</b> include bandwidth requirements, capacity of the base stations, QoS levels priority levels, and costs. If the controller <b>120</b> determines that the search message <b>126</b> should be sent, the procedure continues at step <b>606</b>. Otherwise, the method returns to step <b>602</b>.

At step <b>606</b>, the search message <b>126</b> is generated and transmitted to the wireless communication device <b>106</b>. The controller <b>120</b> generates a search message <b>126</b> in accordance with page messaging techniques. As discussed above, the search message <b>126</b> includes information for adapting the search parameters of the base station searching scheme used by the wireless communication device <b>106</b>. When the invoking the changes contained in the search message <b>126</b>, the wireless communication device <b>106</b> increases the likelihood of detecting the base station <b>302</b> in a shorter time than if the changes are not made. The search message <b>126</b> is transmitted from the reference base station <b>116</b>.

<figref idref="DRAWINGS">FIG. 7</figref> is a block diagram of a communication system <b>700</b> where the transceiver node <b>104</b> is a WLAN access point <b>702</b> and the wireless communication device <b>106</b> is a multimode wireless communication device <b>704</b>. The system <b>700</b> may be implemented using any variety of communication technologies and cell sizes. For the example discussed with reference to <figref idref="DRAWINGS">FIG. 7</figref>, the WLAN access point <b>702</b> provides WLAN wireless service within a WLAN service area and the base station <b>116</b> provides cellular service within a macrocell. The WLAN access point <b>702</b> operates in accordance with a WLAN protocol such as WiFi protocol. The functional blocks of <figref idref="DRAWINGS">FIG. 7</figref> may be implemented using any combination of hardware, software and/or firmware. Two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices. For example, at least portions of the functions of the access router <b>310</b> may be performed by the base station network interface <b>306</b> within the WLAN access point <b>702</b> in some circumstances.

The base station <b>116</b> transmits downlink (forward link) signals <b>122</b> to, and receives uplink (reverse link) signals <b>304</b> from, one or more wireless communication devices to provide wireless communication service. The multimode wireless communication device <b>704</b> may be in any of several states while receiving the WWAN downlink signals that provide system timing. The wireless communication device states may include idle states, dormant states, active states and other traffic and non-traffic states. The wireless communication device <b>704</b> generates and transmits the device beacon in accordance with the system timing and a time and channel assignment. For the example discussed with reference to <figref idref="DRAWINGS">FIG. 7</figref>, the device beacon <b>108</b> is transmitted at a designated time and channel within the uplink WWAN time-channel space. As discussed below with reference to <figref idref="DRAWINGS">FIG. 8</figref>, the device beacon may be transmitted outside the WWAN channels by the multimode wireless communication device in some circumstances.

A WLAN transceiver <b>706</b> within the WLAN access point <b>702</b> facilitates wireless interface with one or more multimode wireless communication devices <b>704</b>. The WLAN transceiver <b>706</b> includes a WLAN receiver <b>708</b> for receiving WLAN uplink signals and a WLAN transmitter <b>710</b> for transmitting WLAN downlink signals in accordance with the WLAN protocol.

The multimode wireless communication device <b>704</b> is any type of communication device that is capable of communicating with the WLAN access point and at least receiving WWAN downlink signals from the base station <b>116</b>. For the example of <figref idref="DRAWINGS">FIG. 7</figref>, the multimode wireless communication device <b>704</b> is capable of receiving, at least non-simultaneously, wireless service from both the WWAN and WLAN systems. The wireless communication device <b>704</b>, sometimes referred to as an access terminal, may be a wireless modem, a personal digital assistant (PDA), cellular telephone, or other such device.

The system infrastructure <b>118</b> includes the controller <b>120</b> that may be implemented as a mobile switching center (MSC), a combination of an MSC and base station controllers (BSCs), or other similar communication controllers and/or servers. The controller <b>120</b> is connected to the base station <b>116</b> through the system infrastructure <b>118</b> and manages communications at least on the WWAN system. A network interface <b>306</b> within the WLAN access point <b>702</b> facilitates communication with an IP network <b>308</b> through an access router <b>310</b>. The network interface <b>306</b> provides packet data communications and facilitates access to the Internet and to an access gateway <b>312</b> in the system infrastructure <b>118</b> through the access router <b>310</b>. In some circumstances the access router <b>310</b> may be implemented as part of the network interface <b>306</b> and the network interface <b>306</b> may directly access the Internet. The access router <b>310</b> may be connected to several access points. In some circumstances, the connection between the access gateway <b>312</b> and the access point <b>702</b> may include a wireless communication link such as satellite communication link or point-to-point microwave link, for example. Also, in some situations, circuit switched connections may be used to connect the access point <b>702</b> to the system infrastructure <b>118</b>. In a typical arrangement, the WLAN access point <b>302</b> is connected to the Internet through an Internet Service Provider (ISP) service provided by a digital subscriber line (DSL) or CATV connection. Accordingly, the access router <b>310</b> is a DSL modem or cable modem in the typical arrangement. In the example, therefore, the system infrastructure <b>118</b> comprises a packet switched core network that includes at least one access gateway <b>312</b>. The access gateway <b>312</b> is a communication interface that allows the access point <b>702</b> to communicate with the system infrastructure <b>118</b>. The WLAN access point receives system timing information form the WWAN through the network interface for this example. In some situations, a WWAN downlink receiver <b>716</b> can be used to intercept WWAN downlink signals to derive the system timing. The block representing the WWAN DL RX <b>716</b> is shown within dashed lines to indicate that the WWAN DL RX <b>716</b> is optional.

For the example of <figref idref="DRAWINGS">FIG. 7</figref>, the device beacon signal <b>108</b> is transmitted within a WWAN uplink channel and the device beacon detector <b>112</b> is formed, at least partially by a WWAN receiver <b>718</b>, a controller <b>714</b> and a memory <b>712</b>. The WWAN receiver <b>718</b> is at least periodically tuned to the appropriate WWAN uplink channel in accordance with the system timing to monitor the device beacon channels.

In addition to other information, the memory <b>712</b> stores communication device identification values corresponding to each communication device <b>704</b> that is authorized to receive service from the access point. The communication device identification value may include an electronic serial number (ESN), Mobile station Equipment Identifier (MEID) or International Mobile Subscriber Identity (IMSI) or other unique data identifying the wireless communication device <b>704</b>. In some implementations, the identification values may be omitted or the access point <b>702</b> may allow communication devices that do not have corresponding identification values stored at the access point <b>702</b> to receive service from the access point <b>702</b>.

During operation, the access point <b>702</b>, monitors, at least periodically, a device beacon channel <b>124</b> which is a wireless channel that may include the device beacon signal <b>108</b>. For the example of <figref idref="DRAWINGS">FIG. 7</figref>, the device beacon signal is transmitted within a sub-carrier time slot. In some circumstances, the time slot is not assigned for any other communications for any frequency. Although the device beacon detector <b>112</b> is formed by at least portions of the controller <b>714</b>, memory <b>712</b> and WWAN receiver <b>718</b>, separate hardware and/or software may be sued to implement the device beacon detector in some cases. Since the WLAN access point receives the WWAN system timing from the system infrastructure <b>118</b>, the WWAN receiver <b>718</b> has adequate system timing information to determine the time slot boundary and the timing of uplink signals. In some circumstances, the device beacon detector <b>112</b> may only search for beacons signals transmitted from wireless communication devices that are authorized to use access point as mentioned above. An authorized list of serial numbers or other device identifiers are stored in memory <b>712</b> at the WLAN access point.

In response to detecting the device beacon signal <b>108</b>, the WLAN access point <b>702</b> sends a device proximity message <b>324</b> to the controller <b>120</b> which invokes the base station <b>116</b> to transmit the search message <b>126</b> to the wireless communication device <b>106</b>. The controller <b>714</b> determines if the device beacon signal <b>108</b> is successfully received at the WLAN access point <b>702</b>. If the signal can be received, the controller <b>714</b> determines that the wireless communication device <b>106</b> is sufficiently close to receive service from the access point <b>702</b>. The controller <b>714</b> determines, or at least estimates, the proximity of the authorized wireless communication device <b>106</b> to the access point <b>702</b> based on one or more characteristics of the uplink signal. In the exemplary embodiment, the detection of an uplink signal from the communication device <b>106</b> is sufficient to determine that the communication device <b>106</b> is within a proximity range. The proximity is used to determine whether the communication device <b>106</b> is possibly within range of the WLAN access point and at least possibly able to receive communication service from the WLAN access point. Therefore, the controller <b>714</b> at least determines whether the communication device is possibly within range of the access point <b>702</b>. If the controller determines that the wireless communication device is possibly in range, the device proximity message <b>324</b> is sent to the controller <b>120</b> in the system infrastructure <b>118</b> which results in the transmission of the search message <b>126</b> to the wireless communication device <b>106</b>.

The controller <b>714</b> may determine whether to transmit the device proximity message <b>324</b> based on factors other than proximity of the wireless communication device <b>106</b> or the detection of the device beacon signal <b>108</b>. For example, factors may include the available capacity of the access point, core network requirements, required bandwidth of the wireless communication device communications, and availability of other, access points, base stations or communication service providers in the area. Accordingly, the access point <b>702</b> may not transmit the device proximity message <b>324</b> even if the wireless communication device <b>106</b> is within range in some circumstances. In some situations, the device proximity message <b>324</b> is transmitted every time a wireless communication device is detected by the access point and the system infrastructure <b>118</b> determines whether to transmit the search message <b>126</b>.

The device proximity message is generated by the controller <b>714</b> and transmitted through the network interface <b>306</b>, through the IP network <b>308</b> and/or the access router <b>310</b> to the access gateway <b>312</b>. The access gateway <b>312</b> routes the device proximity message through the system infrastructure <b>118</b> to the controller <b>120</b>. For the discussed example, the controller <b>120</b> is the same equipment that is used to generate paging messages to the wireless communication device <b>106</b>. The controller <b>120</b> receives the device proximity message and extracts the appropriate information. In response to the device proximity message <b>324</b>, the controller <b>120</b> generates the search message <b>126</b> which is transmitted from the base station <b>116</b> to the wireless communication device <b>106</b>. The search message <b>126</b> triggers an adjustment of the wireless communication device searching scheme that the wireless communication device <b>106</b> employs for searching for access points. In the example of <figref idref="DRAWINGS">FIG. 7</figref>, the multimode wireless communication device <b>704</b> activates a WLAN receiver to search for WLAN signals. In some circumstances, the search message <b>126</b> may specifically instruct the wireless communication device <b>704</b> to search for the access point and/or provide specific frequencies, channels or other information to assist the device <b>704</b> to search for the access point. For the example, the search message <b>126</b> is transmitted using the paging channel. Any suitable downlink channel monitored by the wireless communication device <b>704</b>, however, may be used.

For the present example, the device proximity message <b>324</b> is sent in response to receiving device beacon signal <b>108</b> from an authorized user of the access point <b>702</b>. The search message <b>126</b> is sent to the wireless communication device <b>106</b> in response to receiving the device proximity message <b>324</b> at the controller <b>120</b>. In some situations, however, additional criteria may be evaluated before sending the device proximity message <b>324</b>, the search message <b>126</b>, or before sending both. As discussed above, for example, the access point <b>702</b> may evaluate one or more parameters to determine the proximity of the wireless communication device <b>106</b> to the access point and only send the device proximity message <b>324</b> if the calculated proximity is less than a threshold. Also, the controller <b>120</b> may evaluate system conditions and refrain from sending the search message <b>126</b> if certain system conditions are not met.

Examples of data that may be evaluated by the access point <b>702</b> include the capacity of the access point, bandwidth requirements of the wireless communication device <b>106</b> and a calculated or estimated proximity of the wireless communication device <b>106</b> to the access point <b>702</b>. Accordingly, the access point <b>702</b> may evaluate a characteristic of the device beacon signal <b>108</b> to determine whether to transmit the device proximity message <b>324</b>. In the example, the reception of the device beacon signal <b>108</b> by the WWAN UL receiver <b>320</b> is sufficient to determine that the wireless communication device <b>704</b> is present and that the device proximity message should be transmitted. In other circumstances, other signal characteristics may be evaluated to determine the proximity. Therefore, a characteristic of the device beacon signal <b>108</b> may be any of numerous parameters with any of numerous thresholds depending on the particular implementation and the characteristic may be whether the device beacon signal <b>108</b> is detectable by the WWAN receiver <b>718</b>. Examples of other characteristics include a signal to noise ratio (SNR), bit error rate (BER), power level, signal propagation time, and presence of particular data. An example of technique for determining the proximity is discussed in U.S. patent application Ser. No. 11/565,266 entitled “APPARATUS, SYSTEM AND METHOD FOR MANAGING WIRELESS LOCAL AREA NETWORK SERVICE TO A MULTI-MODE PORTABLE COMMUNICATION DEVICE”, filed on Nov. 30, 2006, and incorporated by reference in its entirety herein.

After receiving the search message, the wireless communication device <b>704</b> searches for an access point in accordance with the adjusted search scheme. In response to the search message, the wireless communication device <b>704</b> activates the appropriate circuitry to receive signals transmitted by the access point <b>702</b> such as a beacon pilot signal or communication pilot signals. Such circuitry is activated in response to reception of the search message. After the access point <b>702</b> is found by the wireless communication device <b>704</b>, the wireless communication device <b>704</b> may engage in a handoff procedure where, after a determination that the wireless communication device <b>704</b> should be handed off to the access point, the system <b>700</b> establishes wireless service to the wireless communication device <b>704</b> from the access point <b>702</b>. Hence, data and control communication is made through communication channel <b>720</b> between the wireless communication device <b>704</b> and the access point <b>702</b>.

<figref idref="DRAWINGS">FIG. 8</figref> is block diagram of a communication system <b>800</b> where device beacon signal is transmitted in a beacon channel <b>124</b> that is not a WWAN channel. The access point <b>802</b> includes a device beacon detector <b>812</b> that is not a WWAN receiver. Any of numerous frequencies and channels can be used for the beacon channel where the beacon channel is based on the WWAN system timing. The beacon may be transmitted in unlicensed frequency bands in some circumstances. The beacon may be transmitted in accordance existing beacon transmissions within 802.11 (WiFi) systems. Beacon transmissions are part of power conversation used by systems such as 802.11. In some circumstances, the timing of these beacon transmissions could be a function of WWAN system timing (assuming WLAN is aware of WWAN timing as well). The system timing provides a reference for the wireless communication device <b>804</b> and the WLAN access point <b>802</b> to use in sending and receiving the device beacon signal <b>108</b>. The system timing can be applied to establish a designated time for transmitting the beacon even though the actual channel is not a WWAN channel.

Operation of the WLAN access point <b>802</b> is as described above with reference to <figref idref="DRAWINGS">FIG. 7</figref> except that the device beacon detector <b>812</b> does not include a WWAN receiver. Accordingly, system timing is applied to the receiver (not shown) within the device beacon detector <b>812</b> to monitor the appropriate beacon channels for device beacons. The system timing may be derived from information sent through the backhaul or may be derived by intercepting WWAN downlink signal <b>122</b>. The WWAN receiver <b>716</b> is shown with dashed lines to illustrate that the receiver is optional. As discussed above with respect to <figref idref="DRAWINGS">FIG. 7</figref>, the WLAN access point <b>802</b> includes a memory <b>712</b> and a controller <b>714</b> which accomplish the pertinent tasks performed in the WLAN access point <b>702</b>. After the access point <b>802</b> is found by the wireless communication device <b>804</b>, the wireless communication device <b>804</b> may engage in a handoff procedure where, after a determination that the wireless communication device <b>804</b> should be handed off to the access point, the system <b>800</b> establishes wireless service to the wireless communication device <b>804</b> from the access point <b>802</b>. Hence, data and control communication is made through communication channel <b>720</b> between the wireless communication device <b>804</b> and the access point <b>802</b>.

<figref idref="DRAWINGS">FIG. 9A</figref> and <figref idref="DRAWINGS">FIG. 9B</figref> are block diagrams of examples of wireless communication devices <b>900</b>, <b>910</b> suitable for use as a wireless communication device <b>106</b> and <figref idref="DRAWINGS">FIG. 9C</figref> and <figref idref="DRAWINGS">FIG. 9D</figref> are block diagrams of examples of multimode wireless communication devices <b>920</b>, <b>930</b> suitable for use as multimode wireless communication devices <b>704</b>. The functional blocks of each of the communication devices shown in <figref idref="DRAWINGS">FIG. 9</figref> A, <figref idref="DRAWINGS">FIG. 9B</figref>, <figref idref="DRAWINGS">FIG. 9C</figref> and <figref idref="DRAWINGS">FIG. 9D</figref> may be implemented using any combination of hardware, software and/or firmware. Two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices. For example, at least portions of the functions of the beacon generator <b>902</b> may be implemented by the controller <b>904</b> in some circumstances.

The wireless communication device <b>900</b> includes at least a beacon generator <b>902</b>, a controller <b>904</b>, a beacon transmitter <b>906</b>, and a WWAN downlink receiver <b>908</b>. As discussed below the beacon transmitter <b>906</b> may include a WWAN transmitter or may include another type of transmitter depending on the channel used for beacon transmission. The WWAN downlink receiver <b>908</b> receives WWAN downlink signal that include WWAN system timing information. The controller derives the system timing information from the signals and the beacon generator applies the WWAN system timing to generate a device beacon. The device beacon is transmitted by the beacon transmitter <b>906</b>.

<figref idref="DRAWINGS">FIG. 9B</figref> is a block diagram of a wireless communication device <b>910</b> where the beacon transmitter includes a WWAN uplink transmitter <b>912</b>. For the example of <figref idref="DRAWINGS">FIG. 9B</figref>, a WWAN transceiver <b>914</b> provides an interface to the WWAN. The WWAN transceiver <b>914</b> includes the WWAN uplink transmitter <b>912</b> and the WWAN downlink receiver <b>908</b>. The transceiver <b>914</b> transmits and receives WWAN signals to facilitate wireless communication with the WWAN. The beacon generator <b>902</b> applies the system timing derived from received WWAN signals to generate a device beacon signal that is transmitted within a WWAN uplink channel that is used as the beacon channel. For the examples of <figref idref="DRAWINGS">FIG. 9B</figref>, <figref idref="DRAWINGS">FIG. 9C</figref> and <figref idref="DRAWINGS">FIG. 9D</figref>, the wireless communication device also includes a memory <b>916</b>. In some cases, the memory is part of the controller. In addition to storing other information and code, the memory stores code, that when run on the controller, manages the functions described herein.

<figref idref="DRAWINGS">FIG. 9C</figref> is a block diagram of multimode wireless communication device <b>920</b> where the beacon is transmitted by the WWAN uplink transmitter. In addition to the functional blocks described above, the multimode wireless communication also includes a WLAN transceiver <b>926</b> for communicating with a WLAN. The WLAN transceiver includes a WLAN UL transmitter <b>922</b> for transmitting WLAN signals and a WLAN downlink receiver <b>924</b> for receiving WLAN signals. The multimode wireless communication device, therefore, may access both the WWAN and the WLAN for communication services. The WWAN signals may be received in any state and provide the WWAN system timing that is applied to generate and transmit the device beacon signal in a WWAN uplink channel designated for device beacons.

<figref idref="DRAWINGS">FIG. 9D</figref> is a block diagram of multimode wireless communication device <b>930</b> where the beacon is transmitted within a beacon channel that is not a WWAN uplink channel. The WWAN signal timing derived from the received WWAN signals is applied to generate the device beacon. The device beacon is transmitted through a beacon channel by a beacon transmitter that may include the WLAN uplink transmitter in some circumstances. In some circumstances, the beacon may be transmitted through separate beacon transmitter through a beacon channel that is not a WWAN or WLAN channel. Such beacon channel may be a Bluetooth channel, for example. In order to illustrate that a separate beacon transmitter is not required when the beacon is transmitted through the WLAN transmitter, the beacon transmitter is shown with dashed lines.

<figref idref="DRAWINGS">FIG. 10</figref> is a flow chart of method performed at the wireless communication device where the transceiver node <b>104</b> is a base station <b>302</b>. The method is performed, at least partially, by executing code on the controller <b>904</b> in the wireless communication device <b>106</b>.

At step <b>1002</b>, WWAN downlink signals are received from a WWAN base station <b>116</b>. The signals are any signals that provide WWAN system timing information and may be received during any of several states of the wireless communication device <b>106</b> including idle (non-traffic) and active (traffic) states. As discussed above, examples of WWAN signals including system timing information include downlink control signals.

At step <b>1004</b>, the system timing is derived from the WWAN signals. Typically, the receiver first synchronizes to the time slot boundaries. After achieving synchronization, the receiver detects and decodes information using knowledge about the frame-structure of WWAN downlink signals.

At step <b>1006</b>, the device beacon signal is transmitted. The device beacon signal is generated and transmitted in accordance with the system timing. The beacon generator applies the system timing and any required scaling to generate a sequence that is mapped to a subcarrier channel of the WWAN uplink frequency-time space.

At step, <b>1008</b>, the search message <b>126</b> is received. In accordance with known techniques, the wireless communication device periodically monitors the downlink paging channels to receive control messaging from the system infrastructure <b>118</b> during traffic and non-traffic states. The search message <b>126</b> is received and deciphered to extract the information related changes to the search parameters.

At step <b>1010</b>, the changes included in the search message are applied to the search scheme of the wireless communication.

At step <b>1012</b>, the newly applied search parameters are applied in searching for an alternate base station. The wireless communication device <b>106</b> tunes the WWAN downlink receiver in accordance to the searching scheme to search for a pilot signal transmitted from the detecting base station <b>114</b> (such as a femtocell base station <b>302</b>). In some circumstances, the wireless communication device <b>106</b> may search for beacons or other signals transmitted from the femtocell base station <b>302</b>.

At step <b>1014</b>, it is determined whether the base station <b>302</b> has been detected. If a signal from the base station <b>302</b> is detected, the method continues at step <b>1016</b>, where a handoff procedure is performed. The procedure may include an analysis to determine whether a handoff should be performed. A handoff is initiated in accordance with known techniques. Otherwise, the method continues at step <b>1018</b>.

At step <b>1018</b>, it is determined whether a new search message is being transmitted. If so, the method returns to step <b>1008</b> to receive the new search message. Otherwise, the method returns to step <b>1012</b> to continue searching for the femtocell base station.

<figref idref="DRAWINGS">FIG. 11</figref> is a flow chart of method performed at the wireless communication device where the transceiver node <b>104</b> is a WLAN access point <b>702</b>, <b>802</b>. The method is performed, at least partially, by executing code on the controller <b>904</b> in the wireless communication device <b>106</b> (<b>920</b>, <b>930</b>).

At step <b>1102</b>, WWAN downlink signals are received from a WWAN base station <b>116</b>. The signals are any signals that provide WWAN system timing information and may be received during any of several states of the wireless communication device <b>106</b> including idle (non-traffic) and active (traffic) states. Examples of WWAN signals including system timing information include downlink control signals

At step <b>1104</b>, the system timing is derived from the WWAN signals. Typically, the receiver first synchronizes to the time slot boundaries. After achieving synchronization, the receiver detects and decodes information using knowledge about the frame-structure of WWAN downlink signals.

At step <b>1106</b>, the device beacon signal is transmitted. The device beacon signal is generated and transmitted in accordance with the system timing. The beacon generator applies the system timing and any required scaling to generate a sequence that is mapped to a subcarrier channel of the WWAN uplink frequency-time space. In some circumstances, the beacon signal may be transmitted within a beacon channel that is not a WWAN uplink channel.

At step, <b>1108</b>, the search message <b>126</b> is received. In accordance with known techniques, the wireless communication device periodically monitors the downlink paging channels to receive control messaging from the system infrastructure <b>118</b> during traffic and non-traffic states. For this example, the search message indicates that the WLAN receiver should be activated to search for signals transmitted by the WLAN access point.

At step <b>1110</b>, the WLAN receiver is activated in response to receiving the search message. Accordingly, the wireless communication device <b>106</b> searches for the WLAN access point. In some circumstances, the wireless communication device <b>106</b> may search for beacons or other signals transmitted from the WLAN access point <b>702</b>, <b>802</b>.

At step <b>1112</b>, it is determined whether WLAN access point <b>702</b>, <b>802</b> has been detected. If a signal from the WLAN access point <b>702</b>, <b>802</b> is detected, the method continues at step <b>1114</b>, where a handoff procedure is performed and a handoff is initiated in accordance with known techniques. Otherwise, the method continues at step <b>1116</b>.

At step <b>1116</b>, it is determined whether a new search message is being transmitted. If so, the method returns to step <b>1108</b> to receive the new search message. Otherwise, the method returns to step <b>1110</b> to continue searching for the femtocell base station.

<figref idref="DRAWINGS">FIG. 12A</figref>, <figref idref="DRAWINGS">FIG. 12B</figref> and <figref idref="DRAWINGS">FIG. 12C</figref> are graphical illustrations of exemplary relationships <b>1200</b>, <b>1250</b> between the device beacon <b>108</b> and the frequency-time space <b>1202</b> of the uplink WWAN channel when the WWAN system utilizes OFDM techniques. The uplink WWAN channels are divided in time and frequency to allocate channels for wireless communication device uplink transmissions. The carriers are divided in time to provide subcarriers <b>1206</b> that are assigned to the different wireless communication devices. <figref idref="DRAWINGS">FIG. 12A</figref>, <figref idref="DRAWINGS">FIG. 12</figref> B and <figref idref="DRAWINGS">FIG. 12C</figref> are provided for general illustrative purposes and implementations may use different numbers of channels and subcarriers. For the example of <figref idref="DRAWINGS">FIG. 12A</figref>, the device beacon is transmitted within the WWAN uplink channel where the beacon signal is at an assigned subcarrier and no other subcarriers are assigned during the beacon transmission time period <b>1204</b>. In <figref idref="DRAWINGS">FIG. 12</figref> B, some or all of the subcarriers within the beacon transmission time period <b>1204</b> may include data or control information. In other arrangements, some or all of the subcarriers <b>1208</b> within the device beacon transmission period <b>1204</b> may be assigned for data or control signaling. The subcarriers that may include data within the beacon transmission period <b>1204</b> are illustrated with boxes containing “x”s in <figref idref="DRAWINGS">FIG. 12B</figref>.

<figref idref="DRAWINGS">FIG. 12C</figref> is a graphical illustration of an example where the device beacon is transmitted outside to the WWAN uplink channel. The device beacon is transmitted at a first frequency during a beacon time period and at a second frequency during a second beacon transmission time period. The first beacon frequency and the second beacon frequency are not within the WWAN uplink channel. The device beacon, however, is transmitted in accordance with the WWAN system timing. Accordingly, the device beacon transmission period <b>1204</b> coincides with subcarrier timing of the WWAN uplink channel.

<figref idref="DRAWINGS">FIG. 13A</figref> is a block diagram of a beacon generator <b>902</b> connected to a beacon transmitter wherein the device beacon is transmitted within the WWAN uplink channel. The beacon generator <b>902</b> may be implemented with any combination of hardware, software, and/or firmware. The blocks shown in <figref idref="DRAWINGS">FIG. 13A</figref> represent functions and may not be performed by distinct hardware blocks. Accordingly, two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices or processes. For the example of <figref idref="DRAWINGS">FIG. 13A</figref>, the device beacon is transmitted within the WWAN uplink channel and the beacon transmitter is the WWAN uplink transmitter <b>912</b>. The description of <figref idref="DRAWINGS">FIG. 13A</figref> may be applied to different types of OFDM systems by modifying the transmitter chain in accordance with known techniques. For example, the beacon generator maybe used in a Single-Carrier FDMA (SC-FDMA) system by appropriately processing the signals using Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) stages at the transmitter and receiver, respectively.

A pilot signal <b>1302</b>, such as baseband bit string, is multiplexed with a beacon message <b>1304</b> in a multiplexer <b>306</b>. The beacon message consists of pre-determined data with a preamble (for acquisition) and/or a repeatable sequence. The beacon message may also include information such at the location of the device <b>106</b> or a transmission power level as well as other information related to the communication device <b>106</b>. The resulting multiplexed signal is scrambled with a pseudorandom sequence <b>1308</b> in a mixer <b>1310</b>. Typically, a scrambling sequence is unique to a specific wireless communication device but other types of sequences (pseudo-unique) are also possible. The mixer <b>1308</b> is an exclusive OR (XOR) circuit in this example. A subcarrier mapping engine <b>1312</b> maps the scrambled beacon and other data <b>1314</b> into the WWAN uplink channel using the WWAN system timing <b>110</b>. In accordance with known techniques, a subcarrier bit and power allocator <b>1316</b> generates the OFDM signal my managing the subcarrier mapping engine <b>1312</b> and adaptive modulator <b>1318</b> which applies BPSK, QPSK, M-QAM or other suitable symbols. Channel condition feedback provided by a receiver is typically applied by the subcarrier bit and power allocator <b>1316</b> to select a different modulation order and power level per subcarrier. In some circumstances, however, the beacon can be transmitted with a pre-determined (fixed) modulation order and power level.

The mapped and processed subcarriers are transmitted by the beacon transmitter which, in this case, is the WWAN uplink transmitter <b>912</b>. The WWAN uplink transmitter <b>912</b> includes an OFDM transmission processor <b>1320</b> and a radio frequency transmitter <b>1322</b>. Accordingly, the WWAN uplink signal including the data and device beacon is transmitted in accordance with OFDM techniques in this example.

<figref idref="DRAWINGS">FIG. 13B</figref> is a block diagram of a beacon generator <b>902</b> where the device beacon is transmitted outside of the WWAN uplink channel. The beacon message <b>1304</b> is scrambled with the PN generator sequence <b>1308</b> in the mixer <b>1308</b>. The WWAN system timing <b>110</b> is applied to the beacon transmitter <b>932</b> to generate and transmit the beacon in accordance with the WWAN system timing. The beacon transmitter <b>932</b>, includes appropriate modulation and amplification circuitry as well as timing circuitry to control transmission timing. For example, a switching function can be applied to the scrambled sequence to align the device beacon transmission period with one or more WWAN uplink subcarriers. The beacon is transmitted by aligning the uplink frame transmitted to the WWAN base station. A simple switch can be turned on at the same time or at an early/late time-offset relative to the beginning of the uplink frame. Perfect synchronization is not required to receive the beacon. The reference timing increases the successful detection of that beacon detector. In some circumstances the beacon can be time-aligned using a local clock where the local clock is synchronized with the WWAN system timing. The clock is used for triggering transmissions and an early or late offset may be applied as needed. Therefore, even though the device beacon signal is transmitted at a frequency other than an uplink WWAN frequency, the beacon signal has a position in time that is based on the WWAN system timing.

<figref idref="DRAWINGS">FIG. 14</figref> is block diagram of a communication system <b>1400</b> where at least two wireless communication devices are able to communicate through a peer to peer link. The wireless communication devices <b>1402</b>, <b>1404</b> each include at least a peer to peer interface <b>1406</b> and a WWAN downlink receiver <b>1408</b>. In some circumstances, one or more of the devices <b>1402</b>, <b>1404</b> may be a multimode wireless communication device and the WWAN downlink receiver <b>1408</b> may be part of a WWAN transceiver that also includes a WWAN uplink transmitter (not shown). The peer to peer interface is a WLAN transceiver in this example. The peer to peer link, however, may utilize other communication technologies, frequencies, and protocols in some circumstances and the peer to peer interfaces may be something other than WLAN transceivers. At least one of the devices <b>1402</b> includes a beacon generator <b>902</b> and at least one includes beacon detector <b>112</b>. Accordingly, <figref idref="DRAWINGS">FIG. 14</figref> illustrates an example where the transceiver node <b>104</b> is the wireless communication device <b>1404</b> and the other wireless communication device <b>1402</b> is the wireless communication device <b>106</b> of <figref idref="DRAWINGS">FIG. 1A</figref>. The wireless communication device <b>1404</b> is, therefore, also an example of the wireless communication device <b>128</b> of <figref idref="DRAWINGS">FIG. 1C</figref>.

Each wireless communication device <b>1402</b>, <b>1404</b> includes a controller <b>1414</b>, <b>1424</b>, a WWAN receiver <b>1408</b> and memory <b>1416</b>, <b>1426</b>. The controller <b>1414</b> (<b>1424</b>) is any electronics, processor, microprocessor or processor arrangement that manages the functions described herein as well as facilitating the overall functionality of the wireless communication device <b>1402</b> (<b>1404</b>). The memory <b>1416</b>, <b>1426</b> is any combination of RAM and/or ROM devices that can store code, ID values and other parameters, values, and data for facilitating the described tasks.

For the example of <figref idref="DRAWINGS">FIG. 14</figref>, the device beacon signal <b>108</b> is transmitted within the WLAN channel. The beacon generator <b>902</b> generates the beacon signal that is transmitted by the WLAN uplink transmitter <b>1422</b> in the peer to peer interface. The device beacon detector <b>112</b> in the wireless communication device <b>1404</b> is formed by the controller <b>1414</b>, memory <b>1416</b> and WLAN uplink receiver <b>1428</b>. Each wireless communication device <b>1402</b>, <b>1404</b> includes a WWAN downlink receiver <b>1408</b> configured to at least receive WWAN downlink signals that provide WWAN system timing information <b>110</b>. Where the device beacon <b>108</b> is transmitted using a channel other than a WLAN channel, the beacon generator and beacon detector are implemented in accordance with the required frequency, channel and protocols of the beacon channel.

After detecting the device beacon signal <b>108</b>, the wireless communication device <b>1404</b> invokes a communication to the wireless communication device <b>1402</b>. For this example, the wireless communication device <b>1404</b> generates and transmits an acknowledgement message <b>1420</b> to the wireless communication device <b>1402</b>. The acknowledgement message <b>1420</b> is transmitted using a WLAN channel. In some circumstances, an acknowledgement message may be sent through the WWAN system. Further, a device proximity message may be sent to the WWAN communication system and the WWAN communication system may notify the wireless communication device <b>1402</b> that the beacon was detected by sending, for example, a search message. The devices <b>1402</b>, <b>1404</b> establish a peer to peer communication link after communications are exchanged in response to the detection of the device beacon signal. Accordingly, the detection of the device beacon signal initiates a peer to peer link establishment procedure. After the peer to peer link is established, the system <b>1400</b> establishes wireless service between the wireless communication devices <b>1402</b> and <b>1404</b>. Hence, data and control communication is made utilizing WLAN downlink receiver <b>1430</b> and uplink transmitter <b>1422</b> of the wireless device <b>1402</b> in communicating with the WLAN downlink transmitter <b>1432</b> and uplink receiver <b>1428</b> of the wireless device <b>1404</b>.

Clearly, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. The above description is illustrative and not restrictive. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.